Projects per year
Abstract
Understanding what drove Northern Hemisphere ice sheet melt during the last deglaciation (21–7 ka) can help constrain how sensitive contemporary ice sheets are to greenhouse gas (GHGs) changes. The roles of orbital forcing and GHGs in the deglaciation have previously been modeled but not yet quantified. Here for the first time we calculate the relative effect of these forcings on the North American deglaciation by driving a dynamical ice sheet model (GLIMMER-CISM) with a set of unaccelerated transient deglacial simulations with a full primitive equation-based ocean-atmosphere general circulation model (FAMOUS). We find that by 9 ka, orbital forcing has caused 50% of the deglaciation, GHG 30%, and the interaction between the two 20%. Orbital forcing starts affecting the ice volume at 19 ka, 2000 years before CO2 starts increasing in our experiments, a delay which partly controls their relative effect.
Original language | English |
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Pages (from-to) | 9970-9979 |
Number of pages | 10 |
Journal | Geophysical Research Letters |
Volume | 42 |
Issue number | 22 |
Early online date | 19 Nov 2015 |
DOIs | |
Publication status | Published - 28 Nov 2015 |
Keywords
- Ice sheets
- Modeling
- Milankovitch theory
- Greenhouse gases
- Insolation forcing
- deglaciation
- ice sheets
- North America
- orbit
- greenhouse gases
- Milankovic
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Dive into the research topics of 'The relative contribution of orbital forcing and greenhouse gases to the North American deglaciation'. Together they form a unique fingerprint.Projects
- 3 Finished
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Modelling ice-sheets, climate and sea-level during the last glacial cycle
Payne, A. J. (Principal Investigator)
1/04/11 → 1/10/15
Project: Research
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QUEST DEGLACIATION: CLIMATE AND BIOGEOCHEMICAL CYCLES DURING THE LAST DEGLACIATION
Shallcross, D. E. (Principal Investigator)
1/07/06 → 1/07/09
Project: Research
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GLACIAL-INTERGLACIAL PLANT MIGRATION ANS VEGETATION CHANGE: A CIRCUMPOLAR DATA SYNTHESIS AND ANALYSIS
Harrison, S. P. (Principal Investigator)
25/08/05 → 25/08/09
Project: Research